Help describe --man-format=plain
  $ ./config.exe help describe --man-format=plain | tee d1
  NAME
         test-describe - Describe a test application.
  
  SYNOPSIS
         test describe [OPTION]... 
  
  DESCRIPTION
         The describe command describes the configuration of a test
         application.
  
         The dot output contains the following elements:
         If vertices
             Represented as circles. Branches are dotted, and the default
             branch is in bold.       Configurables
                                          Represented as rectangles. The order
                                          of the output arrows is the order of
                                          the functor arguments.       
                                                                Data
                                                                dependencies
                                                                           
                                                                Represented as
                                                                dashed arrows.
         App vertices
             Represented as diamonds. The bold arrow is the functor part.
  DESCRIBE OPTIONS
         --dot
             Output a dot description. If no output file is given, it will
             display the dot file using the command given to --dot-command.
  
         --dot-command=COMMAND (absent=xdot)
             Command used to show a dot file. This command should accept a dot
             file on its standard input.
  
         --eval
             Fully evaluate the graph before showing it. The default when the
             unikernel has already been configured.
  
         --no-eval
             Do not evaluate the graph before showing it. See --eval. The
             default when the unikernel has not been configured.
  
  CONFIGURE OPTIONS
         --context-file=FILE (absent=test.context)
             The context file to use.
  
         --dry-run
             Display I/O actions instead of executing them.
  
         -f FILE, --file=FILE, --config-file=FILE (absent=config.ml)
             The configuration file to use.
  
         -o FILE, --output=FILE
             Name of the output file.
  
  APPLICATION OPTIONS
         --hello=VAL (absent=Hello World!)
             How to say hello. 
  
         --vote=VOTE (absent=cat)
             Vote. 
  
         --warn-error=BOOL (absent=false)
             Enable -warn-error when compiling OCaml sources. 
  
  OPTIONS
         --help[=FMT] (default=auto)
             Show this help in format FMT. The value FMT must be one of `auto',
             `pager', `groff' or `plain'. With `auto', the format is `pager` or
             `plain' whenever the TERM env var is `dumb' or undefined.
  
         --version
             Show version information.
  
  COMMON OPTIONS
         --color=WHEN (absent=auto)
             Colorize the output. WHEN must be one of `auto', `always' or
             `never'.
  
         -q, --quiet
             Be quiet. Takes over -v and --verbosity.
  
         -v, --verbose
             Increase verbosity. Repeatable, but more than twice does not bring
             more.
  
         --verbosity=LEVEL (absent=warning)
             Be more or less verbose. LEVEL must be one of `quiet', `error',
             `warning', `info' or `debug'. Takes over -v.
  

Help describe --help=plain
  $ ./config.exe describe --help=plain | tee d2
  NAME
         test-describe - Describe a test application.
  
  SYNOPSIS
         test describe [OPTION]... 
  
  DESCRIPTION
         The describe command describes the configuration of a test
         application.
  
         The dot output contains the following elements:
         If vertices
             Represented as circles. Branches are dotted, and the default
             branch is in bold.       Configurables
                                          Represented as rectangles. The order
                                          of the output arrows is the order of
                                          the functor arguments.       
                                                                Data
                                                                dependencies
                                                                           
                                                                Represented as
                                                                dashed arrows.
         App vertices
             Represented as diamonds. The bold arrow is the functor part.
  DESCRIBE OPTIONS
         --dot
             Output a dot description. If no output file is given, it will
             display the dot file using the command given to --dot-command.
  
         --dot-command=COMMAND (absent=xdot)
             Command used to show a dot file. This command should accept a dot
             file on its standard input.
  
         --eval
             Fully evaluate the graph before showing it. The default when the
             unikernel has already been configured.
  
         --no-eval
             Do not evaluate the graph before showing it. See --eval. The
             default when the unikernel has not been configured.
  
  CONFIGURE OPTIONS
         --context-file=FILE (absent=test.context)
             The context file to use.
  
         --dry-run
             Display I/O actions instead of executing them.
  
         -f FILE, --file=FILE, --config-file=FILE (absent=config.ml)
             The configuration file to use.
  
         -o FILE, --output=FILE
             Name of the output file.
  
  APPLICATION OPTIONS
         --hello=VAL (absent=Hello World!)
             How to say hello. 
  
         --vote=VOTE (absent=cat)
             Vote. 
  
         --warn-error=BOOL (absent=false)
             Enable -warn-error when compiling OCaml sources. 
  
  OPTIONS
         --help[=FMT] (default=auto)
             Show this help in format FMT. The value FMT must be one of `auto',
             `pager', `groff' or `plain'. With `auto', the format is `pager` or
             `plain' whenever the TERM env var is `dumb' or undefined.
  
         --version
             Show version information.
  
  COMMON OPTIONS
         --color=WHEN (absent=auto)
             Colorize the output. WHEN must be one of `auto', `always' or
             `never'.
  
         -q, --quiet
             Be quiet. Takes over -v and --verbosity.
  
         -v, --verbose
             Increase verbosity. Repeatable, but more than twice does not bring
             more.
  
         --verbosity=LEVEL (absent=warning)
             Be more or less verbose. LEVEL must be one of `quiet', `error',
             `warning', `info' or `debug'. Takes over -v.
  

No difference
  $ diff d1 d2
